As I mentioned it is "kind of Art Nouveau". It wasnt really my purpose to copy everything as Mucha did, if I will want to do that I will just colour-pick one of his paintings. I know I used strange colours and it probably is not really working, I'm newbie in colours at all, so this is definitely correct. It is not necessary to use "windows" in art nouveau, just check on google some paintings.. But correct is that there is usually boarder..
I used Paintool SAI for linework (traced my sketch in vector layer and than modified lines), it was my first experience. I really like this software, but as Im newbie there probably are issues.
Regarding anatomy, I have nothing to say. Im not enough educated, so there have to be of course mistakes. Maybe you can draw what do you mean, because it is really difficult for me to see what do you mean especially with neck. I see the arms :/ thanks for pointing that out..
You are not right with thick outer line and really thin lines inside. Lines are to suggest what do you want to show, in some paintings you can see really thick lines even inside of the painting..
Thank you for critique words

EDIT : I attached picture which I was using as inspiration, but of course I was looking at a lot of other stuff on internet.